Spent 4 hours chasing a no start on a Civic, and the answer was staring right at me the whole time
Had a 2003 Civic towed in last Tuesday, cranked fine but would not fire, so I figured it was a fuel issue. I checked the pump, the relay, the filter, everything read good on the gauge. Pulled plugs, they were wet, so I had spark and fuel and still nothing. Spent an hour on grounds, another on the crank sensor, tested the coil twice just to be sure. Around hour four I finally looked at the intake tube I had popped off at the start to get to the throttle body, and there was a rag I shoved in there so nothing would fall in. Pulled it out, hit the key, fired right up. Four hours of my life gone over a shop rag I forgot about ten minutes into the job. So what is the dumbest thing you have chased for way too long before it finally slapped you in the face?
Blocked exhaust will do it every time. Had a guy bring in a mower once, wouldn't start, spent an hour on the carb. Mud dauber nest packed in the muffler the whole time. Bugs and rags, man.